22 



with a sharp hooked point at the extremities. The caudal fins are 

 of considerable size and finely plumose. The oviferous sac is long 

 and narrow, and resembles very much in shape a long stocking or 

 boot. The ova are of a rosy colour. 



3. Streptocephalus ^imilis, Baird (Tab. XXII. fig. 3, 4). An- 

 tennis itiferioribus maris longis, cyliiidricis, appendiee lunulata 

 destitutis, ramis terminalibus prcecedenti similibus,appendicibus 

 antenniformibus filiformibus elongatis ; fronte prolongato, in 

 rostrum hilobatum producto ; ovario externo conico. 



Long, maris 8 lin., fcem. 6 hn. 



Hab. In insula " St. Domingo," in India Occidentali. (/ollegit 

 M. Salle'. Mus. Brit. 



This species, which was found by M. Salle in the island of St. 

 Domingo in the West Indies, is of a slender and cylindrical form. 

 The male is about l^ths of an inch in length, and the female half an 

 inch. The inferior antennae or cephalic horns in the male are large 

 and tortuous ; they are composed of three joints ; the first or 

 basal joint is the largest, is cylindrical, and extends for some distance 

 straight forwards ; the second, smaller than the basal, is also cylin- 

 drical, curves slightly at first, then bends suddenly backwards upon 

 itself ; the third or terminal joint beuds as suddenly forwards and 

 terminates in a club-shaped extremity, which divides into two 

 branches, one longer than the other, terminating in a long filiform 

 process ; the other flatter, shorter, and dividing into two shorter fili- 

 form processes of unequal length. The antenniform appendage is 

 long and cylindrical, rather stout, and springs from close to the ex- 

 tremity of basal joint. The basal joint is destitute of the lanceolate, 

 toothed appendage on internal edge, which we see in the preceding 

 species. The superior antennae are long and slender, and consist 

 of two joints, the basal one much shorter than the second. The 

 male organs are rather long, cylindrical, and of a horny texture. 

 The front of the head is prolonged into a beak, which is flat, rather 

 broad and slightly lobed at the extremity. Feet short. Abdomen 

 slender. Caudal appendages of moderate length, and beset on each 

 side with numerous short and plumose setae. 



The cephalic horns in the female are short, thick, and terminate in 

 a short spine at the extremity. The ovarian bag is conical, acute, 

 and the ova are of an ochreous colour. 



The chief differences between this species and S. cafer consist, in 

 the male, in the shape of the front of the head, the organs of gene- 

 ration, and in the inferior anteimae having no lamina with teeth on 

 the basal joint ; in the female, in the shape of the external ovary. 



Genus Chirocephalus, Prevost. 



Corpus molle, cylindricum ; segmentum caudale pinnis duabus 

 ciliatis instrnctum ; pedes undecim ; antennce inferiores maris 

 validce, biarticulata, appendicibus digitiformibus fiabelliformi- 

 busque armatce. 



This genus closely resembles the two preceding in the shape and 



